Modular power line network adapter

ABSTRACT

A modular feed-though adapter that allows an electrical connection to a power line network adapter without “using up” an electrical outlet is described. In one embodiment, the modular feed-through adapter also provides noise filtering to protect electrical equipment plugged into the feed-through outlet. The noise filtering also protects the power line network data signals from noise generated by the devices plugged into the feed-through adapter. In one embodiment, the network connections provided by the feed-through adapter are low voltage connections, thus allowing the network connections from the feed-through adapter to be safely plugged directly into low-voltage equipment such as computer network cards and the like. In one embodiment, the modular adapter includes a ball to couple network data signals to the power line.

REFERENCE TO RELATED APPLICATIONS

This present application is a continuation of application Ser. No.09/902,454, filed Jul. 10, 2001, U.S. Pat. No. 6,747,859, which claimspriority from U.S. Provisional Application Ser. No. 60/217,364, filedJul. 11, 2000, titled “MODULAR POWER LINE NETWORK ADAPTER,” the entirecontents of the above-listed applications are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to adapters for power line communication systems,in particular, the invention relates to adapters that connect a powerline network modem to an electrical outlet or electrical power cord.

2. Description of the Related Art

The widespread availability of computers, especially personal computers,has led to a rapid increase in the number of computer networks.Networking two or more computers together allows the computers to shareinformation, file resources, printers, etc. Connecting two or morepersonal computers and printers together to form a network is, inprinciple, a simple task. The computers and printers are simplyconnected together using a cable, and the necessary software isinstalled onto the computers. In network terminology, the cable is thenetwork medium and the computers and printers are the network nodes.Unfortunately, in practice, creating a computer network is often notquite as simple as it sounds. Typically, a user will encounter bothsoftware and hardware problems in attempting to configure a computernetwork.

When configuring a network in a home or small office, users oftenencounter hardware difficulties insomuch as it is usually necessary toinstall a network cable to connect the various network nodes. In a homeor office environment, it can be very difficult to install the necessarycabling when the computers are located in different rooms or ondifferent floors. Network systems that use radio or infrared radiationare known, but such systems are subject to interference and governmentregulation, and thus are far less common than systems that rely on aphysical connection such as a wire or cable.

Virtually all residential and commercial buildings in the U.S. Are wiredwith electrical power lines, and using the existing power lines as anetwork medium to carry data is both convenient and efficient. Access tothe power lines, for both power and data, is typically provided byconventional two-pronged or three-pronged electrical outlets. In mosthomes and office buildings, several electrical outlets are provided ineach room. Nevertheless, many people find that there are never enoughavailable outlets. To combat this problem, a wide variety ofmulti-outlet adapters have been marketed.

The multi-outlets adapters come in many forms, but they all have thecommon goal of expanding the number of devices that can be plugged intoa wall outlet. One common type of multi-outlet adapter used withcomputer equipment is the surge-suppressor strip. The surge-suppressorstrips usually include a power cord that plugs into an existing walloutlet, a switch, a circuit breaker, and several outlets. Thesurge-protector strips include surge suppressors and noise filters toprotect the computer equipment from voltage spikes and noise oftenpresent on the power line.

Unfortunately, the surge suppressors and noise filters in thesurge-suppressor strips often cause problems with power line networkingsystems because the noise filter treats the network data signals asnoise that must be removed. Therefore, it is often desirable for thepower line networking system to have direct access to the electricalpower outlets, rather than the outlets provided by the surge-suppressorstrip.

Power line network systems are often installed by homeowners and smallbusiness owners who have little, if any, technical training. Some usershave encountered difficulty, and dissatisfaction, with prior power linenetwork systems because the user, unwilling to give up an electricaloutlet, plugged the power line equipment into a surge-suppressor strip(sometimes rendering the power line network equipment partiallyinoperative due to the noise filters in the strip). Moreover, previousembodiments of power line adapters have met with some consumerresistance because the need for direct access to the power outlet “usedup” an outlet that the consumer wanted to use for other purposes. Insome cases, the size existing power line equipment that plugged into anelectrical outlet forced the user to move furniture away from the outlet(such situations can occur, for example, when the outlet being used fora computer or printer lies behind a desk or bookcase).

SUMMARY OF THE INVENTION

The present invention solves these and other problems by providing acompact modular feed-though adapter that allows an electrical connectionto a power line network adapter without “using up” an electrical outlet.In so doing, the present invention greatly increases the convenience andusability of power line network equipment. Power line network equipmentconfigured according to the present invention is much easier for theuser to install than prior systems and significantly reduces the chancethat a user will have problems due to incorrect installations. Thefeed-through adapter allows the user to plug the power line networkadapter directly into the wall without sacrificing an electrical outlet.

In one embodiment, the modular feed-through adapter also provides noisefiltering to protect electrical equipment plugged into the feed-throughoutlet. Unlike a conventional surge-suppressor strip that filters alloutputs, putting the noise filter in the feed-through adapter providesfiltering where desirable (e.g. To protect a computer) and avoidsprotective filtering where such filtering would be undesirable (e.g. Inthe power line network data path). The noise filtering also protects thepower line network data signals from noise generated by the devicesplugged into the feed-through adapter. In one embodiment, the networkconnections provided by the feed-through adapter are low voltageconnections, thus allowing the network connections from the feed-throughadapter to be safely plugged directly into low-voltage equipment such ascomputer network cards and the like.

One embodiment includes a self-contained feed-through power line networkadapter that provides an electrical power connection to a power line,and a network data connection to a computer or other device. In oneembodiment, the self-contained unit includes an electrical plugconfigured to plug into one socket, such as the lower socket, of anelectrical power outlet without covering other sockets in the electricaloutlet. The self-contained adapter includes a feed-through output socketand a network data/power connector. In one embodiment, the feed-throughsocket includes a filter to reduce the amount of power line noise andvoltage spikes that reaches the equipment plugged into the feed-throughsocket. The filter also reduces the amount of noise that reaches thedata/power connector from the device plugged into the feed-throughoutlet. In one embodiment, the self-contained network adapter includes apower line network interface and one or more network ports to allownetwork connections between the self-contained network adapter and acomputer or other device.

In one embodiment, a self-contained adapter includes an electrical plugconfigured to plug into two or more sockets of an electrical poweroutlet. The two-outlet self-contained adapter includes two feed-throughoutput sockets and a network data/power connector. In one embodiment,the feed-through socket includes a ground-fault interrupter circuit forsafety and a filter to reduce the amount of power line noise and voltagespikes that reaches the equipment plugged into the feed-through sockets.The filter also reduces the amount of noise that reaches the data/powerconnector from the device plugged into the feed-through outlets.

In one embodiment, a modular feed-through power line network adapterprovides an electrical power connection to a power line, and a power anddata connection to a power line network adapter. The modular adapterprovides a feed-through output socket and a power/network connector. Inone embodiment, the feed-through socket includes a filter to reduce theamount of power line noise and other voltage transients that reach theequipment plugged into the feed-through socket. The filter also reducesthe amount of noise that reaches the data/power connector from thedevice plugged into the feed-through outlet. In one embodiment, thedata/power connector is configured to receive a data/power cableconnected to a power line network adapter module. In one embodiment, thedata/power connector provides 110-volt power to the network adaptermodule. In one embodiment, the data/power connector provides relativelylower voltage power to the network adapter module. In one embodiment,the data/power connector provides data signals to a self-powered thenetwork adapter card or module. One embodiment includes a modularfeed-through power line network adapter configured as a surge-suppressorstrip that includes a network power/data connector.

One embodiment includes a modular feed-through power line networkadapter that provides an inline electrical power connection to acomputer power-supply connector plug and a data connection to a powerline network adapter.

In one embodiment, a low pass filter reduces the amount of power linenoise that reaches the device plugged into the feed-through outlet. Thelow pass filter also reduces the noise that reaches the data/powerconnector from a device plugged into a feed-through outlet. In oneembodiment, the low pass filter is an LC filter.

In one embodiment, the modular adapter includes a ball to couple networkdata signals to the power line.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the invention will now be described withreference to the following drawings.

FIG. 1 is a schematic diagram of the electrical powerline wiring in atypical home or small office and a networking system that uses theelectrical powerlines as the network medium.

FIGS. 2A and B show one embodiment of a self-contained feed-throughpower line network adapter that provides an electrical power connectionto a power line, and a network data connection to a computer or otherdevice.

FIGS. 3A and B show one embodiment of a self-contained feed-throughpower line network adapter that provides a ground-fault protectedelectrical power connection to a power line, and a network dataconnection to a computer or other network device.

FIG. 4 shows one embodiment of a modular feed-through power line networkadapter that provides an electrical power connection to a power line,and a power and data connection to a power line network adapter.

FIG. 5 shows one embodiment of a modular feed-through power line networkadapter that provides an electrical power connection to a power line,and a data connection to a power line network adapter card.

FIG. 6 shows one embodiment of a modular feed-through power line networkadapter that provides a multi-output electrical power connection to apower line, and a data connection to a power line network adapter.

FIG. 7 shows one embodiment of a modular feed-through power line networksurge-suppressor strip that provides a multi-output electrical powerconnection to a power line, and a data connection to a power linenetwork adapter.

FIG. 8 shows one embodiment of a modular feed-through power line networkadapter that provides an inline electrical power connection to acomputer power-supply power line, and a data connection to a power linenetwork adapter.

FIG. 9 is a block diagram of one embodiment of a feed-through power linenetwork adapter that provides a filtered feed-through port for poweringother electrical devices and an unfiltered output for providing powerand data to a power line network interface.

FIG. 10 is a block diagram of one embodiment of a filtered feed-throughadapter as described in connection with FIG. 9.

FIG. 11 is a block diagram of one embodiment of a feed-through powerline network adapter that provides a filtered feed-through port forpowering other electrical devices and a data output for providing datato a power line network interface, and, optionally, low voltage power tothe power line network interface.

FIG. 12 is a block diagram of one embodiment of a feed-through powerline network adapter that provides a filtered feed-through port forpowering other electrical devices and a ball for providing data to apower line network interface.

In the drawings, like reference numbers are used to indicate like orfunctionally similar elements. The first digit of each three-digitreference number generally indicates the figure number in which thereferenced item first appears. The first two digits of each four-digitreference number generally indicate the figure number in which thereferenced item first appears.

DETAILED DESCRIPTION

FIG. 1 is a schematic diagram of the electrical powerline wiring in atypical home or small office and a networking system that uses theelectrical powerlines as the network medium. Power is received from anexternal power grid on a first hot wire 120, a second hot wire 122, anda neutral wire 121. The hot wires 120 and 122 carry an alternatingcurrent at 60 Hz (hertz) at a voltage that is nominally 110 volts RMSwith respect to the neutral wire 121. The hot wires 120 and 122 are 180deg. out of phase with respect to each other, such that the voltagemeasured between the first hot wire 120 and the second hot wire 122 is220 volts RMS.

Only one of the hot wires 120, 122 is provided to smaller appliances,lights, computers, etc. For example, as shown in FIG. 1, the second hotwire 122 and the neutral wire 121 are provided to a blender 140.

The first hot wire 120, the neutral wire 121, and a ground wire 123 areprovided to a power input of a printer 105. The first hot wire 120 andthe neutral wire 121 are also provided to a powerline data port of apowerline network module 101. A data port on the powerline networkmodule 101 is provided to a data port on the printer 108.

The second hot wire 122, the neutral wire 121, and the ground wire 123are provided to a power input of a computer 106. The second hot wire 122and the neutral wire 121 are provided to a powerline data port of apowerline network module 102. A data port on the powerline networkmodule 102 is provided to a network data port on the computer 106.

The second hot wire 122, the neutral wire 121, and the ground wire 123are provided to a power input of a networked device 107. The second hotwire 122 and the neutral wire 121 are provided to a powerline data portof a powerline network module 103. A data port on the powerline networkmodule 103 is provided to a network data port on the device 107. Thedevice 107 can be any networked appliance or device in the home oroffice, including, for example, an alarm system controller, an alarmsystem sensor, a controllable light, a controllable outlet, a networkedkitchen appliance, a networked audio system, a networked television orother audio-visual system, etc.

The printer 105, the computer 106, and the networked device 107communicate using the electrical powerlines (the hot wires 120, 122, andthe neutral wire 121). The powerline network modules 101–103 receivenetwork data, modulate the data into a format suitable for thepowerline, and couple the modulated data onto the powerline. Thepowerline network modules also receive modulated data from thepowerlines, and demodulate the data.

Devices such as the blender 140 and the computer 106 introduce noiseonto the powerlines. This noise includes motor noise, switchingtransients, etc. The network modules 101–103 are configured to providean acceptable maximum data error rate in the presence of this noise.

FIG. 2 shows one embodiment of a self-contained feed-through power linenetwork adapter 200 that provides an electrical power connection to apower line, and a network data connection to a computer or other devicewithout “using up” an electrical outlet. The adapter 200 includes a plug202 and a feed-through outlet 207. In one embodiment, the plug 202 andthe outlet 207 are three-pronged devices for connecting to hot, neutral,and ground. In one embodiment, the plug 202 and the outlet 207 aretwo-pronged devices for connecting to hot and neutral. The adapter 200also includes computer data connectors such as a USB connector 256 and aparallel-port connector 206. The data connectors 256 and/or 206 can alsobe configured for Ethernet, firewire, fiber-optic cable, and the like. Acomputer, printer, appliance, or other network enabled device isconnected by a network cable to the data connectors 256 and/or 206.

The adapter 200 is configured such that when the plug 202 is pluggedinto a standard wall outlet, the adapter 200 does not cover othersockets in the wall outlet (as shown by an outline 220). The adapter 200includes internal electronic circuits that modulate data received at theconnectors 256 or 206 and couple the modulated data onto the power linethrough the plug 202. The internal circuits also receive modulated datafrom the plug 202, demodulate the data, and provide the demodulated datato the connectors 256 and 206. As shown in connection with FIGS. 9–12below, in one embodiment, a filter is provided between the feed-throughoutlet 207 and the internal electronic circuits to prevent noiseintroduced by a device plugged into the outlet 207 from reaching theinternal circuits. Likewise, the filter keeps a portion of the noise andtransients from the power line from reaching the outlet 207 and thus anydevices plugged into the outlet 207 are thereby partially protected frompower line noise and transients.

FIG. 3 shows one embodiment of a self-contained feed-through power linenetwork adapter 300 that provides a ground-fault interrupter (GFI)protected electrical power connection to a power line, and a networkdata connection to a computer or other device without “using up” anelectrical outlet. The adapter 300 includes three-pronged plugs 302 and303. The adapter 300 includes GFI-protected feed-through outlets 307 and308. A test button 311 and a reset button 310 are also provided toenable the conventional GFI test and reset functions. The adapter 300also includes the computer data connectors 256 and 206.

The adapter 300 is configured such that when the plugs 302 and 303 areplugged into a standard wall outlet, the outlet becomes a ground-faultinterrupter outlet. Like the adapter 200, the adapter 300 includesinternal electronic circuits that modulate data received at theconnectors 256 or 206 and couple the modulated data onto the power linethrough the plug (302 or 303). The internal circuits also receivemodulated data from the plug (302 or 303), demodulate the data, andprovide the demodulated data to the connectors 256 and 206. As shown inconnection with FIGS. 9–12 below, in one embodiment, a filter isprovided between the GFI-protected feed-through outlets 307 and 308 andthe internal electronic circuits to prevent noise introduced by a deviceplugged into the outlets 307 and 308 from reaching the internalcircuits. Likewise, the filter keeps a portion of the noise andtransients from the power line from reaching the outlets 307 and 308 andthus any devices plugged into the outlets 307 and 308 are therebypartially protected from power line noise and transients. In oneembodiment, a GFI circuit protects both the outlets 307, 308, theinternal electronic network circuits (including the connectors 206,256).

FIG. 4 shows one embodiment of a modular feed-through power line networkadapter 400 that provides an electrical power connection to a powerline, and a network power and/or data connection to a power line networkmodem 450 without “using up” an electrical outlet. The adapter 400includes a plug 401 and a feed-through outlet 402. In one embodiment,the plug 401 and the outlet 402 are three-pronged devices for connectingto hot, neutral, and ground. In one embodiment, the plug 401 and theoutlet 402 are two-pronged devices for connecting to hot and neutral.The adapter 400 also includes a connector 403 for providing power and/ordata. An interface cable 405 is provided with a plug 404 on one end anda plug 407 on the other end. The plug 404 is provided to the connector403 and the plug 407 is provided to a connector 410 on the modem 450,thus allowing power and/or data to flow between the adapter 400 and themodem 450.

The modem 450 includes internal circuits for modulating and demodulatingdata from the power line. The modem 450 also includes network interfaceconnectors such as the connectors 206 and 256 as described in connectionwith FIG. 2 above. In one embodiment, the module 400 is configured suchthat when it is plugged into one socket of the standard wall outlet 201,it does not cover up the other socket(s) in the wall outlet 201.Internal circuitry of the adapter 400 is described in connection withFIG. 9–12.

The connectors 404 and/or 407 can be omitted and the cable 405 connecteddirectly to the adapter 400 and/or the modem 450 respectively.

As shown in FIG. 5, in one embodiment, the modular feed-through powerline network adapter 400 and cable 405 can also be connected to acomputer interface card 500. In one embodiment, the card 500 includesthe connector 410 and the modulation and demodulation circuits describedin connection with the modem 450 above. The card 500 can be a plug-incard such as for example a PCI card, an ISA card, a Macintosh plug-incard, a daughter board, etc. The card 500 can also be a computermotherboard, a device specific card such as a printer controller card,an appliance controller card, etc. The connector 404 and/or 407 can beomitted and the cable 405 connected directly to the adapter 400 and/orthe card 500 respectively.

In one embodiment, the card 500 is configured to be self-powered (thatis, powered by the computer or device it is connected to) and thus theadapter 400 does not need to supply power. In this embodiment, the cable405 need only provide a data connection between the adapter 400 and thecard 500 (see e.g. the embodiments shown in connection with FIG. 11 or12).

FIG. 6 shows one embodiment of a modular feed-through power line networkadapter 600 that provides a multi-output electrical power connection toa power line, and the data connector 403. The adapter 600 is similar tothe adapter 400 and includes the plug 401, the outlet 402, and theconnector 403. The adapter 600 also includes additional outlets 601 and602.

FIG. 7 shows one embodiment of a modular feed-through power line networkoutlet strip 700 that provides a multi-output electrical powerconnection to a power line, and the data connector 403. The stripincludes a plug 701 and a main power cable 702 (in lieu of the plug 401shown in connection with FIG. 6). The strip 700 includes the outlets 402and additional outlets 706–708. A switch 704 is provided to allow theoutlets 401 and 706–708 to be disconnected from the electrical powersupply. In one embodiment, the outlet strip 700 includes surgesuppressors for one or more of the outlets 401 and 706–708.

In one embodiment, the strip 700 is configured as a self-containedoutlet strip and network power adapter including the network dataconnector 256 and the modulation and demodulation circuits described inconnection with the modem 450.

In one embodiment, the strip 700 is configured as an electrical powerline adapter including the connector 403 to be used in connection with amodem, such as, for example, the modem 450 or the network card 500.

FIG. 8 shows one embodiment of a modular feed-through power line networkadapter 800 that includes an electrical connector 808 configured to pluginto a standard computer power-supply connector 802. The adapter 800includes a standard computer power-supply connector 810 to allow acomputer power cord 809 to be plugged into the adapter 800. The adapter800 includes the connector 403 to allow a connection to the computercard 500 (or motherboard, etc.) as described in connection with FIG. 5above. Electrically, the adapter 800 can be configured as shown inconnection with FIGS. 9–12.

FIG. 9 is a schematic diagram of one embodiment of a filteredfeed-through adapter circuit 900. The circuit 900 is a representativeembodiment of the adapters described above in connection with FIGS. 2–8.The adapter 900 receives power from a power line, such as for example,the plug 202, 302, 303, 401, 701 and the like, including an input hotline 901, and input neutral line 902, and an input ground line 903 (theground is optional in some embodiments). The hot line 901, the neutralline 902 and the ground line 903 are provided to a hot input, neutralinput and ground input, respectively, of an optional GFI circuit 960. Ahot output, a neutral output, and a ground output of the GFI circuit 960are provided, respectively, to a hot input, a neutral input, and aground input of a filter 905. If the GFI circuit 960 is omitted then thehot line 901, the neutral line 902 and the ground line 903 are providedto the hot input, the neutral input, and the ground input, respectively,of the filter 905. A hot output, a neutral output, and a ground outputof the filter 905 are provided, respectively, to a hot feed-throughoutput 921, a neutral feed-through output 922, and a ground feed-throughoutput 923. The feed-through outputs 921–923 are provided to thefeed-through output outlets such as, for example, the outlets 207, 307,308, 402, 601–602, and 708-708 and the like.

The hot input, the neutral input, and the ground inputs of the filter905 are also provided to a hot network output 911, a neutral networkoutput 912, and an optional ground network output 913. In oneembodiment, the network outputs 911–913 are provide to, for example, theconnector 403 described above in connection with FIGS. 4-8. The filter905 can be a lowpass filter or a bandpass filter. In one embodiment, thefilter 905 includes surge suppressors. In one embodiment, the filter 905includes surge suppressors to clamp transient high-voltage spikes torelatively safe levels. In one embodiment, the filter 905 includesinrush current limiters to limit high current surges.

FIG. 10 is a schematic diagram of one embodiment of the filter 905,shown as a filter 1005. In the filter 1005, the hot input is provided toa first terminal of an inductor 1001. A second terminal of the inductor1001 is provided to a first terminal of a capacitor 1004 and to a firstterminal of an optional inductor 1003. A second terminal of thecapacitor 1002 is provided to the neutral input of the filter 1005. Thesecond terminal of the inductor 1003 is provided to a hot output of thefilter 1005 and to a first terminal of a capacitor 1004. A secondterminal of the capacitor 1004 is provided to the second terminal of thecapacitor 1002. The neutral input of the filter 1005 is provided to theneutral output of the filter 1005. The ground input of the filter 1005is provided to the ground output of the filter 1005. The optionalcapacitor 1004 can be omitted. The optional inductor 1003 can bereplaced with a wire.

FIG. 11 is a schematic diagram of one embodiment of a filteredfeed-through adapter circuit 1100. The circuit 1100 is a representativeembodiment of the adapters described above on connection with FIGS. 2–8.The adapter 1100 is similar in many respects to the adapter 900 (shownin FIG. 9) and includes the inputs 901–903, the optional GFI 960, thefilter 905, and the outputs 921–923. However, in the adapter 1100, thehot input and the neutral input of the filter 905 are provided to hotinput and a neutral input of a ball 1105. The ground input of the filter905 is provided to the ground output 913. A first ball outputs 1111 anda second ball output 1112 are provided to a data output, such as, forexample, the connector 403 described above in connection with FIGS. 4–8.The ball separates the connector 403 from the high voltage power lines.In one embodiment, the ball 1105 extracts data signals from the powerline and provides the data signals to the connector 403. In oneembodiment, the ball is a step-down transformer that provides both dataand low-voltage power signals to the data connector 403. One skilled inthe art will recognize that the ball is typically bi-directional and theuse of the terms input and output to describe the ports of the ball isfor convenience, and not by way of limitation, such that the ball willalso couple data from the lines 1111, 1112 onto the power lines 901,902.

FIG. 12 is a schematic diagram of a ball 1205, the ball 1205 being oneembodiment of the ball 1105 shown in FIG. 11. In the ball 1205, the ballhot input is provided to a first terminal of a capacitor 1211 and theball neutral input is provided to a first terminal of a capacitor 1212.A second terminal of the capacitor 1211 is provided to a first terminalof a primary winding of a ball transformer 1210. A second terminal ofthe capacitor 1212 is provided to a second terminal of the primarywinding of a ball transformer 1210. A first terminal of a secondarywinding of the ball transformer 1210 is provided to the output 1111 anda second terminal of the secondary winding of the ball transformer 1210is provided to the output 1112.

In one embodiment, the ball transformer 1210 is a ferrite-coretransformer. In one embodiment, the ball transformer 1210 is apowdered-metal core transformer.

Although this invention has been described in terms of a certainembodiment, other embodiments apparent to those of ordinary skill in theart also are within the scope of this invention. For example, theconnectors 404 and/or 407 can be omitted and the cable 405 connecteddirectly to the appropriate device. Various other changes andmodifications may be made without departing from the spirit and scope ofthe invention. Accordingly, the scope of the invention is defined by theclaims that follow.

1. A feed-through power line network adapter comprising: a housing; anelectrical power plug attached to said housing for plugging into astandard electrical outlet; a surge suppressor in said housing, saidsurge suppressor configured to receive power from said electrical powerplug; a first feed-through output socket configured to receivesurge-suppressed power from said surge suppressor; a voltage step-downbandpass filter in said housing, said filter configured to receive powerfrom said electrical power plug without passing through said surgesuppressor; a network data/power connector attached to said housing,said connector configured to receive relatively low-voltage power fromsaid filter; and a ground-fault interrupter circuit electricallyinterposed between said electrical power plug and said surge suppressor.2. A feed-through power line network adapter comprising: an electricalpower plug for plugging into a standard electrical outlet saidelectrical power plug comprising a housing; a filter in said housing,said filter configured to receive power from said electrical power plug;a first feed-through output socket disposed in said housing, said firstfeed-through output socket configured to receive power from said filter;a network connector configured to receive power from said electricalpower plug without passing through said filter; and a ball in saidhousing, said ball configured to couple modulated data signals from saidnetwork connector to said electrical power plug.
 3. A feed-through powerline network adapter comprising: a housing; an electrical power plugattached to said housing for plugging into a standard electrical outlet;a filter in said housing, said filter configured to receive power fromsaid electrical power plug; a first feed-through output socket attachedto said housing, said first feed-through output socket configured toreceive power from said filter; a data connector configured to receivepower from said electrical power plug without passing through saidfilter; and a voltage step-down transformer in said housing, saidstep-down transformer having a high-voltage primary winding connected tosaid electrical power plug and a low-voltage secondary configured toprovide power to said data connector.
 4. The feed-through power linenetwork adapter of claim 3, said filter composing a surge suppressor. 5.The feed-through power line network adapter of claim 3, said filtercomprising a bandpass filter.
 6. The feed-through power line networkadapter of claim 3, said filter comprising a lowpass filter.
 7. Aninline-electrical power adapter, said adapter comprising: a firstelectrical connector, said first electrical connector configured to pluginto a power connector of a standard computer power supply; a secondelectrical connector, said second electrical connector configured toreceive a standard computer power cable connector; a filter disposedinside said adapter, said filter configured. To receive electrical powerfrom said second electrical connector and provide filtered power to saidfirst electrical connector; a ball provided to said adapter; and a dataconnector, said data connector configured to couple power line datanetwork signals to said second electrical connector through said ball,said ball comprising a step-down transformer such that full power linevoltages do not appear at terminals of said data connector.